contrib/fwd: rewrite rule generate to use xtables api
authorJo-Philipp Wich <jow@openwrt.org>
Wed, 16 Dec 2009 02:02:45 +0000 (02:02 +0000)
committerJo-Philipp Wich <jow@openwrt.org>
Wed, 16 Dec 2009 02:02:45 +0000 (02:02 +0000)
contrib/fwd/src/Makefile
contrib/fwd/src/fwd.h
contrib/fwd/src/fwd_addr.c
contrib/fwd/src/fwd_addr.h
contrib/fwd/src/fwd_config.c
contrib/fwd/src/fwd_rules.c

index 89efd7b065ea1526b0248539fbe76c6256a8593b..c147c67060bea86312b3305bf71e63c77228c937 100644 (file)
@@ -1,4 +1,4 @@
-CFLAGS  := -g -Wall -I./uci -I./iptables-1.4.5/include
+CFLAGS  := -ggdb3 -O0 -Wall -I./uci -I./iptables-1.4.5/include
 LDFLAGS := -luci -liptc -lxtables -ldl -L./iptables-1.4.5/libiptc/.libs -L./iptables-1.4.5/.libs -Wl,--export-dynamic
 
 fwd:
index c93c0aff9033dd0a31e8278007523d38a7c9e42b..0228daf7b6d3de6920c08e894b4a30ce294dc966 100644 (file)
@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <stdarg.h>
 #include <stdlib.h>
+#include <getopt.h>
 #include <netinet/in.h>
 
 #if 0
@@ -36,7 +37,7 @@ enum fwd_policy {
        FWD_P_UNSPEC = 0,
        FWD_P_DROP   = 1,
        FWD_P_REJECT = 2,
-       FWD_P_ACCEPT = 3        
+       FWD_P_ACCEPT = 3
 };
 
 enum fwd_stype {
@@ -103,6 +104,9 @@ struct fwd_defaults {
 struct fwd_zone {
        char *name;
        struct fwd_network_list *networks;
+       struct fwd_data *forwardings;
+       struct fwd_data *redirects;
+       struct fwd_data *rules;
        enum fwd_policy input;
        enum fwd_policy forward;
        enum fwd_policy output;
@@ -127,6 +131,7 @@ struct fwd_redirect {
        struct fwd_cidr      *dest_ip;
        struct fwd_portrange *dest_port;
        struct fwd_proto     *proto;
+       int clone; /* true if rule is cloned (tcpudp -> tcp + udp) */
 };
 
 struct fwd_rule {
@@ -140,6 +145,7 @@ struct fwd_rule {
        struct fwd_proto     *proto;
        struct fwd_icmptype  *icmp_type;
        enum fwd_policy target;
+       int clone; /* true if rule is cloned (tcpudp -> tcp + udp) */
 };
 
 struct fwd_include {
index df5d8e7c2aefa44ab5479327f63d326a80294d6a..fd277e9e0f54b8a5714b5ab98f04862bd556a3c0 100644 (file)
@@ -95,8 +95,8 @@ struct fwd_addr_list * fwd_get_addrs(int fd, int family)
                        {
                                if( rtatp->rta_type == IFA_ADDRESS )
                                {
-                                       memcpy(&entry->ipaddr, (char *) RTA_DATA(rtatp), rtatp->rta_len);
-                                       entry->prefix = rtmp->ifa_prefixlen;
+                                       memcpy(&entry->ipaddr.addr, (char *) RTA_DATA(rtatp), rtatp->rta_len);
+                                       entry->ipaddr.prefix = rtmp->ifa_prefixlen;
                                        entry->family = family;
                                }
                                else if( rtatp->rta_type == IFA_LABEL)
index 1a28f646415a70a9606bba3f083fa411e3e82f85..44465705af827fcd3e7e729ee6045a03365ad881 100644 (file)
@@ -33,11 +33,7 @@ struct fwd_addr_list {
        char label[IFNAMSIZ];
        int family;
        int index;
-       unsigned int prefix;
-       union {
-               struct in_addr v4;
-               struct in6_addr v6;
-       } ipaddr;
+       struct fwd_cidr ipaddr;
        struct fwd_addr_list *next;
 };
 
index 11fd458325ae52c4395b5b82cbebacb49c2aa6dc..a77965cf5a1a246ce0e3d830541f84ce9cd37429 100644 (file)
@@ -163,11 +163,17 @@ fwd_read_mac(struct uci_context *uci, const char *s, const char *o, struct fwd_m
        {
                if( (*m = fwd_alloc_ptr(struct fwd_mac)) != NULL )
                {
+                       unsigned int i1, i2, i3, i4, i5, i6;
+
                        if( sscanf(val, "%2x:%2x:%2x:%2x:%2x:%2x",
-                               (unsigned int *)&(*m)->mac[0], (unsigned int *)&(*m)->mac[1],
-                               (unsigned int *)&(*m)->mac[2], (unsigned int *)&(*m)->mac[3],
-                               (unsigned int *)&(*m)->mac[4], (unsigned int *)&(*m)->mac[5]) == 6
+                               &i1, &i2, &i3, &i4, &i5, &i6) == 6
                        ) {
+                               (*m)->mac[0] = (unsigned char)i1;
+                               (*m)->mac[1] = (unsigned char)i2;
+                               (*m)->mac[2] = (unsigned char)i3;
+                               (*m)->mac[3] = (unsigned char)i4;
+                               (*m)->mac[4] = (unsigned char)i5;
+                               (*m)->mac[5] = (unsigned char)i6;
                                return 0;
                        }
                }
@@ -470,17 +476,14 @@ static void fwd_read_forwards_cb(
        struct fwd_zone *zsrc  = NULL;
        struct fwd_zone *zdest = NULL;
 
-       if( (src = fwd_read_string(uci, s, "src")) != NULL )
-       {
-               if( !(zsrc = fwd_lookup_zone(cv->head, src)) )
-                       fwd_read_error("section '%s' references unknown src zone '%s'!", s, src);
-       }
-
-       if( (dest = fwd_read_string(uci, s, "dest")) != NULL )
-       {
-               if( !(zdest = fwd_lookup_zone(cv->head, dest)) )
-                       fwd_read_error("section '%s' references unknown dest zone '%s'!", s, dest);
-       }
+       if( !(src = fwd_read_string(uci, s, "src")) )
+               fwd_read_error("section '%s' is missing 'src' option!", s);
+       else if( !(zsrc = fwd_lookup_zone(cv->head, src)) )
+               fwd_read_error("section '%s' references unknown src zone '%s'!", s, src);
+       else if( !(dest = fwd_read_string(uci, s, "dest")) )
+               fwd_read_error("section '%s' is missing 'dest' option!", s);
+       else if( !(zdest = fwd_lookup_zone(cv->head, dest)) )
+               fwd_read_error("section '%s' references unknown dest zone '%s'!", s, dest);
        
        if( (dtn = fwd_alloc_ptr(struct fwd_data)) != NULL )
        {
@@ -490,8 +493,17 @@ static void fwd_read_forwards_cb(
                dtn->section.forwarding.masq = fwd_read_bool(uci, s, "masq", 0);
 
                dtn->type = FWD_S_FORWARD;
-               dtn->next = cv->cursor;
-               cv->cursor = dtn;
+
+               if( zsrc )
+               {
+                       dtn->next = zsrc->forwardings;
+                       zsrc->forwardings = dtn;
+               }
+               else
+               {
+                       dtn->next = cv->cursor;
+                       cv->cursor = dtn;
+               }
        }
        else
        {
@@ -560,8 +572,8 @@ static void fwd_read_redirects_cb(
                dtn->section.redirect.dest_port = dest_port;
 
                dtn->type = FWD_S_REDIRECT;
-               dtn->next = cv->cursor;
-               cv->cursor = dtn;
+               dtn->next = zsrc->redirects;
+               zsrc->redirects = dtn;
 
                if( (proto != NULL) && (proto->type == FWD_PR_TCPUDP) )
                {
@@ -582,10 +594,11 @@ static void fwd_read_redirects_cb(
                        dtn2->section.redirect.src_dport = src_dport;
                        dtn2->section.redirect.dest_ip   = dest_ip;
                        dtn2->section.redirect.dest_port = dest_port;
+                       dtn2->section.redirect.clone     = 1;
 
                        dtn2->type = FWD_S_REDIRECT;
-                       dtn2->next = cv->cursor;
-                       cv->cursor = dtn2;
+                       dtn2->next = zsrc->redirects;
+                       zsrc->redirects = dtn2;
                }
        }
        else
@@ -665,8 +678,8 @@ static void fwd_read_rules_cb(
                dtn->section.rule.target    = fwd_read_policy(uci, s, "target");
 
                dtn->type = FWD_S_RULE;
-               dtn->next = cv->cursor;
-               cv->cursor = dtn;
+               dtn->next = zsrc->rules;
+               zsrc->rules = dtn;
 
                if( (proto != NULL) && (proto->type == FWD_PR_TCPUDP) )
                {
@@ -688,10 +701,11 @@ static void fwd_read_rules_cb(
                        dtn2->section.rule.dest_ip   = dest_ip;
                        dtn2->section.rule.dest_port = dest_port;
                        dtn2->section.rule.target    = dtn->section.rule.target;
+                       dtn2->section.rule.clone     = 1;
 
                        dtn2->type = FWD_S_RULE;
-                       dtn2->next = cv->cursor;
-                       cv->cursor = dtn2;
+                       dtn2->next = zsrc->rules;
+                       zsrc->rules = dtn2;
                }
        }
        else
@@ -868,26 +882,39 @@ void fwd_free_config(struct fwd_data *h)
                        case FWD_S_ZONE:
                                fwd_free_ptr(h->section.zone.name);
                                fwd_free_networks(h->section.zone.networks);
+                               fwd_free_config(h->section.zone.rules);
+                               fwd_free_config(h->section.zone.redirects);
+                               fwd_free_config(h->section.zone.forwardings);
                                break;
 
                        case FWD_S_REDIRECT:
-                               fwd_free_ptr(h->section.redirect.src_ip);
-                               fwd_free_ptr(h->section.redirect.src_mac);
-                               fwd_free_ptr(h->section.redirect.src_port);
-                               fwd_free_ptr(h->section.redirect.src_dport);
-                               fwd_free_ptr(h->section.redirect.dest_ip);
-                               fwd_free_ptr(h->section.redirect.dest_port);
+                               /* Clone rules share all pointers except proto.
+                   Prevent a double-free here */          
+                               if( ! h->section.redirect.clone )
+                               {
+                                       fwd_free_ptr(h->section.redirect.src_ip);
+                                       fwd_free_ptr(h->section.redirect.src_mac);
+                                       fwd_free_ptr(h->section.redirect.src_port);
+                                       fwd_free_ptr(h->section.redirect.src_dport);
+                                       fwd_free_ptr(h->section.redirect.dest_ip);
+                                       fwd_free_ptr(h->section.redirect.dest_port);
+                               }
                                fwd_free_ptr(h->section.redirect.proto);
                                break;
 
                        case FWD_S_RULE:
-                               fwd_free_ptr(h->section.rule.src_ip);
-                               fwd_free_ptr(h->section.rule.src_mac);
-                               fwd_free_ptr(h->section.rule.src_port);
-                               fwd_free_ptr(h->section.rule.dest_ip);
-                               fwd_free_ptr(h->section.rule.dest_port);
+                               /* Clone rules share all pointers except proto.
+                   Prevent a double-free here */          
+                               if( ! h->section.rule.clone )
+                               {
+                                       fwd_free_ptr(h->section.rule.src_ip);
+                                       fwd_free_ptr(h->section.rule.src_mac);
+                                       fwd_free_ptr(h->section.rule.src_port);
+                                       fwd_free_ptr(h->section.rule.dest_ip);
+                                       fwd_free_ptr(h->section.rule.dest_port);
+                                       fwd_free_ptr(h->section.rule.icmp_type);
+                               }
                                fwd_free_ptr(h->section.rule.proto);
-                               fwd_free_ptr(h->section.rule.icmp_type);
                                break;
 
                        case FWD_S_DEFAULTS:
@@ -896,7 +923,7 @@ void fwd_free_config(struct fwd_data *h)
                                break;
                }
 
-               free(h);
+               fwd_free_ptr(h);
                h = e;
        }
 
index c3d4ebbe5332fadab9e7f1da00211fb4963dd33e..e6604911a73b6c59b03bc1189e5b1d35627cb65d 100644 (file)
 #include "fwd_rules.h"
 #include "fwd_xtables.h"
 
-static void
-fwd_ipt_rule_append(struct fwd_ipt_rulebuf *r, const char *fmt, ...)
-{
-       int len = 0;
-       char buf[256]; buf[0] = 0;
-
-       va_list ap;
-       va_start(ap, fmt);
-       len = vsnprintf(buf, sizeof(buf), fmt, ap);
-       va_end(ap);     
-
-       if( len > 0 )
-       {
-               r->buf = realloc(r->buf, r->len + len + 1);
-               memcpy(&r->buf[r->len], buf, len);
-               r->buf[r->len + len] = 0;
-               r->len += len;
-       }
-}
-
-static struct fwd_ipt_rulebuf * fwd_ipt_init(const char *table)
-{
-       struct fwd_ipt_rulebuf *r;
-
-       if( (r = fwd_alloc_ptr(struct fwd_ipt_rulebuf)) != NULL )
-       {
-               fwd_ipt_rule_append(r, IPT " -t %s", table);
-               return r;
-       }
-
-       return NULL;
-}
-
-static void fwd_ipt_add_srcport(
-       struct fwd_ipt_rulebuf *r, struct fwd_portrange *p
-) {
-       if( p != NULL )
-       {
-               if( p->min < p->max )
-                       fwd_ipt_rule_append(r, " --sport %u:%u", p->min, p->max);
-               else
-                       fwd_ipt_rule_append(r, " --sport %u", p->min);
-       }
-}
-
-static void fwd_ipt_add_destport(
-       struct fwd_ipt_rulebuf *r, struct fwd_portrange *p
-) {
-       if( p != NULL )
-       {
-               if( p->min < p->max )
-                       fwd_ipt_rule_append(r, " --dport %u:%u", p->min, p->max);
-               else
-                       fwd_ipt_rule_append(r, " --dport %u", p->min);
-       }
-}
-
-static void fwd_ipt_add_proto(
-       struct fwd_ipt_rulebuf *r, struct fwd_proto *p
-) {
-       if( p != NULL )
-       {
-               switch( p->type )
-               {
-                       case FWD_PR_TCPUDP:
-                               fwd_ipt_rule_append(r, " -p tcp -p udp");
-                               break;
-
-                       case FWD_PR_TCP:
-                               fwd_ipt_rule_append(r, " -p tcp");
-                               break;
-
-                       case FWD_PR_UDP:
-                               fwd_ipt_rule_append(r, " -p udp");
-                               break;
-
-                       case FWD_PR_ICMP:
-                               fwd_ipt_rule_append(r, " -p icmp");
-                               break;
-
-                       case FWD_PR_ALL:
-                               fwd_ipt_rule_append(r, " -p all");
-                               break;
-
-                       case FWD_PR_CUSTOM:
-                               fwd_ipt_rule_append(r, " -p %u", p->proto);
-                               break;
-               }
-       }
-}
-
-static void fwd_ipt_add_srcaddr(
-       struct fwd_ipt_rulebuf *r, struct fwd_cidr *c
-) {
-       if( c != NULL )
-       {
-               if( c->prefix < 32 )
-                       fwd_ipt_rule_append(r, " -s %s/%u",
-                               inet_ntoa(c->addr), c->prefix);
-               else
-                       fwd_ipt_rule_append(r, " -s %s", inet_ntoa(c->addr));
-       }
-}
-
-static void fwd_ipt_add_destaddr(
-       struct fwd_ipt_rulebuf *r, struct fwd_cidr *c
-) {
-       if( c != NULL )
-       {
-               if( c->prefix < 32 )
-                       fwd_ipt_rule_append(r, " -d %s/%u",
-                               inet_ntoa(c->addr), c->prefix);
-               else
-                       fwd_ipt_rule_append(r, " -d %s", inet_ntoa(c->addr));
-       }
-}
-
-static void fwd_ipt_add_srcmac(
-       struct fwd_ipt_rulebuf *r, struct fwd_mac *m
-) {
-       if( m != NULL )
-       {
-               fwd_ipt_rule_append(r,
-                       " -m mac --mac-source %02x:%02x:%02x:%02x:%02x:%02x",
-                       m->mac[0], m->mac[1], m->mac[2],
-                       m->mac[3], m->mac[4], m->mac[5]);
-       }
-}
-
-static void fwd_ipt_add_icmptype(
-       struct fwd_ipt_rulebuf *r, struct fwd_icmptype *i
-) {
-       if( i != NULL )
-       {
-               if( i->name )
-                       fwd_ipt_rule_append(r, " --icmp-type %s", i->name);
-               else if( i->code > -1 )
-                       fwd_ipt_rule_append(r, " --icmp-type %u/%u", i->type, i->code);
-               else
-                       fwd_ipt_rule_append(r, " --icmp-type %u", i->type);
-       }
-}
-
-static void fwd_ipt_add_dnat_target(
-       struct fwd_ipt_rulebuf *r, struct fwd_cidr *c, struct fwd_portrange *p
-) {
-       if( c != NULL )
-       {
-               fwd_ipt_rule_append(r, " -j DNAT --to-destination %s",
-                       inet_ntoa(c->addr));
-
-               if( (p != NULL) && (p->min < p->max) )
-                       fwd_ipt_rule_append(r, ":%u-%u", p->min, p->max);
-               else if( p != NULL )
-                       fwd_ipt_rule_append(r, ":%u", p->min);
-       }
-}
-
-static void fwd_ipt_add_policy_target(
-       struct fwd_ipt_rulebuf *r, enum fwd_policy p
-) {
-       fwd_ipt_rule_append(r, " -j %s",
-               (p == FWD_P_ACCEPT)
-                       ? "handle_accept"
-                       : (p == FWD_P_REJECT)
-                               ? "handle_reject"
-                               : "handle_drop"
-       );
-}
-
-static void fwd_ipt_add_comment(
-       struct fwd_ipt_rulebuf *r, const char *t, struct fwd_zone *z,
-       struct fwd_network_list *n, struct fwd_network_list *n2
-) {
-       if( (n != NULL) && (n2 != NULL) )
-               fwd_ipt_add_format(r, " -m comment --comment '%s:%s src:%s dest:%s'",
-                       t, z->name, n->name, n2->name);
-       else if( (n == NULL) && (n2 != NULL) )
-               fwd_ipt_add_format(r, " -m comment --comment '%s:%s dest:%s'",
-                       t, z->name, n2->name);
-       else
-               fwd_ipt_add_format(r, " -m comment --comment '%s:%s src:%s'",
-                       t, z->name, n->name);
-}
-
-static void fwd_ipt_exec(struct fwd_ipt_rulebuf *r)
-{
-       if( r->len )
-               printf("%s\n", r->buf);
-
-       fwd_free_ptr(r->buf);
-       fwd_free_ptr(r);
-}
 
 /* -P <chain> <policy> */
 static void fwd_r_set_policy(
@@ -252,7 +59,7 @@ static void fwd_r_drop_invalid(struct iptc_handle *h, const char *chain)
        {
                if( (m = fwd_xt_get_match(r, "state")) != NULL )
                {
-                       fwd_xt_parse_match(r, m, "--state", "INVALID", 0);
+                       fwd_xt_parse_match(r, m, "--state", "INVALID");
                        fwd_xt_get_target(r, "DROP");
                        fwd_xt_exec_rule(r, chain);
                }
@@ -269,7 +76,7 @@ static void fwd_r_accept_related(struct iptc_handle *h, const char *chain)
        {
                if( (m = fwd_xt_get_match(r, "state")) != NULL )
                {
-                       fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED", 0);
+                       fwd_xt_parse_match(r, m, "--state", "RELATED,ESTABLISHED");
                        fwd_xt_get_target(r, "ACCEPT");
                        fwd_xt_exec_rule(r, chain);
                }
@@ -320,17 +127,17 @@ static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
                /* -m tcp --syn */
                if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
                {
-                       fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+                       fwd_xt_parse_match(r, m, "--syn");
                }
 
                /* -m limit --limit x/second --limit-burst y */
                if( (m = fwd_xt_get_match(r, "limit")) != NULL )
                {
                        sprintf(buf, "%i/second", def->syn_rate);
-                       fwd_xt_parse_match(r, m, "--limit", buf, 0);
+                       fwd_xt_parse_match(r, m, "--limit", buf);
 
                        sprintf(buf, "%i", def->syn_burst);
-                       fwd_xt_parse_match(r, m, "--limit-burst", buf, 0);
+                       fwd_xt_parse_match(r, m, "--limit-burst", buf);
                }
 
                /* -j RETURN; -A syn_flood */
@@ -356,7 +163,7 @@ static void fwd_r_add_synflood(struct iptc_handle *h, struct fwd_defaults *def)
                /* -m tcp --syn */
                if( (m = fwd_xt_get_match(r, "tcp")) != NULL )
                {
-                       fwd_xt_parse_match(r, m, "--syn", NULL, 0);
+                       fwd_xt_parse_match(r, m, "--syn");
                }
 
                /* -j syn_flood; -A INPUT */
@@ -385,7 +192,7 @@ static void fwd_r_handle_reject(struct iptc_handle *h)
                /* -j REJECT --reject-with tcp-reset */
                if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
                {
-                       fwd_xt_parse_target(r, t, "--reject-with", "tcp-reset", 0);
+                       fwd_xt_parse_target(r, t, "--reject-with", "tcp-reset");
                }
 
                /* -A handle_reject */
@@ -399,7 +206,7 @@ static void fwd_r_handle_reject(struct iptc_handle *h)
                if( (t = fwd_xt_get_target(r, "REJECT")) != NULL )
                {
                        fwd_xt_parse_target(r, t, "--reject-with",
-                               "icmp-port-unreachable", 0);
+                               "icmp-port-unreachable");
                }
 
                /* -A handle_reject */
@@ -441,6 +248,155 @@ static void fwd_r_handle_accept(struct iptc_handle *h)
        }
 }
 
+/* add comment match */
+static void fwd_r_add_comment(
+       struct fwd_xt_rule *r, const char *t, struct fwd_zone *z,
+       struct fwd_network_list *n, struct fwd_network_list *n2
+) {
+       struct xtables_match *m;
+       char buf[256];
+
+       if( (m = fwd_xt_get_match(r, "comment")) != NULL )
+       {
+               if( (n != NULL) && (n2 != NULL) )
+                       snprintf(buf, sizeof(buf), "%s:%s src:%s dest:%s",
+                               t, z->name, n->name, n2->name);
+               else if( (n == NULL) && (n2 != NULL) )
+                       snprintf(buf, sizeof(buf), "%s:%s dest:%s", t, z->name, n2->name);
+               else
+                       snprintf(buf, sizeof(buf), "%s:%s src:%s", t, z->name, n->name);
+
+               fwd_xt_parse_match(r, m, "--comment", buf);
+       }
+}
+
+/* add --sport (if applicable) */
+static void fwd_r_add_sport(
+       struct fwd_xt_rule *r, struct fwd_portrange *p
+) {
+       int proto = r->entry->ip.proto;
+       char buf[12];
+       struct xtables_match *m;
+
+       /* have portrange and proto is tcp or udp ... */
+       if( (p != NULL) && ((proto == 6) || (proto == 17)) )
+       {
+               /* get match ... */
+               if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
+               {
+                       snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
+                       fwd_xt_parse_match(r, m, "--sport", buf);
+               }
+       }
+}
+
+/* add --dport (if applicable) */
+static void fwd_r_add_dport(
+       struct fwd_xt_rule *r, struct fwd_portrange *p
+) {
+       int proto = r->entry->ip.proto;
+       char buf[12];
+       struct xtables_match *m;
+
+       /* have portrange and proto is tcp or udp ... */
+       if( (p != NULL) && ((proto == 6) || (proto == 17)) )
+       {
+               /* get match ... */
+               if( (m = fwd_xt_get_match(r, (proto == 6) ? "tcp" : "udp")) != NULL )
+               {
+                       snprintf(buf, sizeof(buf), "%u:%u", p->min, p->max);
+                       fwd_xt_parse_match(r, m, "--dport", buf);
+               }
+       }
+}
+
+/* add --icmp-type (of applicable) */
+static void fwd_r_add_icmptype(
+       struct fwd_xt_rule *r, struct fwd_icmptype *i
+) {
+       int proto = r->entry->ip.proto;
+       struct xtables_match *m;
+       char buf[32];
+
+       /* have icmp-type and proto is icmp ... */
+       if( (i != NULL) && (proto == 1) )
+       {
+               /* get match ... */
+               if( (m = fwd_xt_get_match(r, "icmp")) != NULL )
+               {
+                       if( i->name[0] )
+                               snprintf(buf, sizeof(buf), "%s", i->name);
+                       else
+                               snprintf(buf, sizeof(buf), "%u/%u", i->type, i->code);
+
+                       fwd_xt_parse_match(r, m, "--icmp-type", buf);
+               }
+       }
+}
+
+/* add -m mac --mac-source ... */
+static void fwd_r_add_srcmac(
+       struct fwd_xt_rule *r, struct fwd_mac *mac
+) {
+       struct xtables_match *m;
+       char buf[18];
+
+       if( mac != NULL )
+       {
+               if( (m = fwd_xt_get_match(r, "mac")) != NULL )
+               {
+                       snprintf(buf, sizeof(buf), "%02x:%02x:%02x:%02x:%02x:%02x",
+                               mac->mac[0], mac->mac[1], mac->mac[2],
+                               mac->mac[3], mac->mac[4], mac->mac[5]);
+
+                       fwd_xt_parse_match(r, m, "--mac-source", buf);
+               }
+       }
+}
+
+/* add policy target */
+static void fwd_r_add_policytarget(
+       struct fwd_xt_rule *r, enum fwd_policy pol
+) {
+       switch(pol)
+       {
+               case FWD_P_ACCEPT:
+                       fwd_xt_get_target(r, "handle_accept");
+                       break;
+
+               case FWD_P_REJECT:
+                       fwd_xt_get_target(r, "handle_reject");
+                       break;
+
+               case FWD_P_DROP:
+               case FWD_P_UNSPEC:
+                       fwd_xt_get_target(r, "handle_drop");
+                       break;
+       }
+}
+
+/* add dnat target */
+static void fwd_r_add_dnattarget(
+       struct fwd_xt_rule *r, struct fwd_cidr *c, struct fwd_portrange *p
+) {
+       struct xtables_target *t;
+       char buf[32];
+
+       if( c != NULL )
+       {
+               if( (t = fwd_xt_get_target(r, "DNAT")) != NULL )
+               {
+                       if( p != NULL )
+                               snprintf(buf, sizeof(buf), "%s:%u-%u",
+                                       inet_ntoa(c->addr), p->min, p->max);
+                       else
+                               snprintf(buf, sizeof(buf), "%s", inet_ntoa(c->addr));
+
+                       fwd_xt_parse_target(r, t, "--to-destination", buf);
+               }
+       }
+}
+
 
 static void fwd_ipt_defaults_create(struct fwd_data *d)
 {
@@ -494,9 +450,10 @@ static void fwd_ipt_defaults_create(struct fwd_data *d)
        fwd_r_jump_chain(h_filter, "FORWARD", "forwardings");
        fwd_r_new_chain(h_nat, "zonemasq");
        fwd_r_new_chain(h_nat, "redirects");
+       fwd_r_new_chain(h_nat, "loopback");
        fwd_r_jump_chain(h_nat, "POSTROUTING", "zonemasq");
        fwd_r_jump_chain(h_nat, "PREROUTING", "redirects");
-       fwd_r_jump_chain(h_nat, "POSTROUTING", "redirects");
+       fwd_r_jump_chain(h_nat, "POSTROUTING", "loopback");
 
        /* standard drop, accept, reject chain */
        fwd_r_handle_drop(h_filter);
@@ -589,12 +546,22 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
 {
        struct fwd_data *e;
        struct fwd_zone *z;
-       struct fwd_ipt_rulebuf *b;
        struct fwd_rule *c;
        struct fwd_redirect *r;
        struct fwd_forwarding *f;
        struct fwd_addr_list *a, *a2;
        struct fwd_network_list *n, *n2;
+       struct fwd_proto p;
+
+       struct fwd_xt_rule *x;
+       struct xtables_match *m;
+       struct xtables_target *t;
+
+       struct iptc_handle *h_filter, *h_nat;
+
+       if( !(h_filter = iptc_init("filter")) || !(h_nat = iptc_init("nat")) )
+               fwd_fatal("Unable to obtain libiptc handle");
+
 
        if( !(z = fwd_lookup_zone(h, net)) )
                return;
@@ -612,10 +579,13 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
        {
                printf("\n# Net %s (%s) - masq\n", n->name, n->ifname);
 
-               b = fwd_ipt_init("nat");
-               fwd_ipt_add_format(b, " -A zonemasq -o %s -j MASQUERADE", n->ifname);
-               fwd_ipt_add_comment(b, "masq", z, NULL, n);
-               fwd_ipt_exec(b);
+               if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+               {
+                       fwd_xt_parse_out(x, n, 0);                                      /* -o ... */
+                       fwd_xt_get_target(x, "MASQUERADE");                     /* -j MASQUERADE */
+                       fwd_r_add_comment(x, "masq", z, NULL, n);       /* -m comment ... */
+                       fwd_xt_exec_rule(x, "zonemasq");                        /* -A zonemasq */
+               }
        }
 
        /* Build MSS fix rule */
@@ -623,12 +593,26 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
        {
                printf("\n# Net %s (%s) - mtu_fix\n", n->name, n->ifname);
 
-               b = fwd_ipt_init("filter");
-               fwd_ipt_add_format(b,
-                       " -A mssfix -o %s -p tcp --tcp-flags SYN,RST SYN"
-                       " -j TCPMSS --clamp-mss-to-pmtu", n->ifname);
-               fwd_ipt_add_comment(b, "mssfix", z, NULL, n);
-               fwd_ipt_exec(b);
+               if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+               {
+                       p.type = FWD_PR_TCP;
+                       fwd_xt_parse_out(x, n, 0);                                      /* -o ... */
+                       fwd_xt_parse_proto(x, &p, 0);                           /* -p tcp */
+
+                       /* -m tcp --tcp-flags SYN,RST SYN */
+                       if( (m = fwd_xt_get_match(x, "tcp")) != NULL )
+                               fwd_xt_parse_match(x, m, "--tcp-flags", "SYN,RST", "SYN");
+
+                       /* -j TCPMSS --clamp-mss-to-pmtu */
+                       if( (t = fwd_xt_get_target(x, "TCPMSS")) != NULL )
+                               fwd_xt_parse_target(x, t, "--clamp-mss-to-pmtu");
+
+                       /* -m comment ... */
+                       fwd_r_add_comment(x, "mssfix", z, NULL, n);
+
+                       /* -A mssfix */
+                       fwd_xt_exec_rule(x, "mssfix");
+               }
        }
 
        /* Build intra-zone forwarding rules */
@@ -641,12 +625,14 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
                                n->name, n->ifname, z->name, n->name, n->ifname,
                                z->name, n2->name, n2->ifname);
 
-                       b = fwd_ipt_init("filter");
-                       fwd_ipt_add_format(b, " -A zones -i %s -o %s",
-                               n->ifname, n2->ifname);
-                       fwd_ipt_add_policy_target(b, z->forward);
-                       fwd_ipt_add_comment(b, "zone", z, n, n2);
-                       fwd_ipt_exec(b);
+                       if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+                       {
+                               fwd_xt_parse_in(x, n, 0);                               /* -i ... */
+                               fwd_xt_parse_out(x, n2, 0);                             /* -o ... */
+                               fwd_r_add_policytarget(x, z->forward);  /* -j handle_... */
+                               fwd_r_add_comment(x, "zone", z, n, n2); /* -m comment ... */
+                               fwd_xt_exec_rule(x, "zones");                   /* -A zones */
+                       }
                }
        }
 
@@ -661,12 +647,14 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
                                f->dest->name, n2->name, n2->ifname);
 
                        /* Build forwarding rule */
-                       b = fwd_ipt_init("filter");
-                       fwd_ipt_add_format(b, " -A forwardings -i %s -o %s",
-                               n->ifname, n2->ifname);
-                       fwd_ipt_add_policy_target(b, FWD_P_ACCEPT);
-                       fwd_ipt_add_comment(b, "forward", z, n, n2);
-                       fwd_ipt_exec(b);
+                       if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+                       {
+                               fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
+                               fwd_xt_parse_out(x, n2, 0);                                     /* -o ... */
+                               fwd_r_add_policytarget(x, FWD_P_ACCEPT);        /* -j handle_... */
+                               fwd_r_add_comment(x, "forward", z, n, n2);      /* -m comment ... */
+                               fwd_xt_exec_rule(x, "forwardings");                     /* -A forwardings */
+                       }
                }
        }
 
@@ -677,43 +665,49 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
                        n->name, n->ifname, z->name, n->name, n->ifname);
 
                /* DNAT */
-               b = fwd_ipt_init("nat");
-               fwd_ipt_add_format(b, " -A redirects -i %s -d %s",
-                       n->ifname, inet_ntoa(a->ipaddr.v4));
-               fwd_ipt_add_proto(b, r->proto);
-               fwd_ipt_add_srcaddr(b, r->src_ip);
-               fwd_ipt_add_srcport(b, r->src_port);
-               fwd_ipt_add_destport(b, r->src_dport);
-               fwd_ipt_add_srcmac(b, r->src_mac);
-               fwd_ipt_add_dnat_target(b, r->dest_ip, r->dest_port);
-               fwd_ipt_add_comment(b, "redir", z, n, NULL);
-               fwd_ipt_exec(b);
+               if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+               {
+                       fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
+                       fwd_xt_parse_src(x, r->src_ip, 0);                      /* -s ... */
+                       fwd_xt_parse_dest(x, &a->ipaddr, 0);            /* -d ... */
+                       fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
+                       fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
+                       fwd_r_add_dport(x, r->src_dport);                       /* --dport ... */
+                       fwd_r_add_srcmac(x, r->src_mac);                        /* -m mac --mac-source ... */
+                       fwd_r_add_dnattarget(x, r->dest_ip, r->dest_port);      /* -j DNAT ... */
+                       fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
+                       fwd_xt_exec_rule(x, "redirects");                       /* -A redirects */
+               }
 
                /* Forward */
-               b = fwd_ipt_init("filter");
-               fwd_ipt_add_format(b, " -A redirects -i %s", n->ifname);
-               fwd_ipt_add_proto(b, r->proto);
-               fwd_ipt_add_srcmac(b, r->src_mac);
-               fwd_ipt_add_srcaddr(b, r->src_ip);
-               fwd_ipt_add_srcport(b, r->src_port);
-               fwd_ipt_add_destaddr(b, r->dest_ip);
-               fwd_ipt_add_destport(b, r->dest_port);
-               fwd_ipt_add_policy_target(b, FWD_P_ACCEPT);
-               fwd_ipt_add_comment(b, "redir", z, n, NULL);
-               fwd_ipt_exec(b);
+               if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+               {
+                       fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
+                       fwd_xt_parse_src(x, r->src_ip, 0);                      /* -s ... */
+                       fwd_xt_parse_dest(x, r->dest_ip, 0);            /* -d ... */
+                       fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
+                       fwd_r_add_srcmac(x, r->src_mac);                        /* -m mac --mac-source ... */
+                       fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
+                       fwd_r_add_dport(x, r->dest_port);                       /* --dport ... */
+                       fwd_r_add_policytarget(x, FWD_P_ACCEPT);        /* -j handle_accept */
+                       fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
+                       fwd_xt_exec_rule(x, "redirects");                       /* -A redirects */
+               }
 
                /* Add loopback rule if neither src_ip nor src_mac are defined */
                if( !r->src_ip && !r->src_mac )
                {
-                       b = fwd_ipt_init("nat");
-                       fwd_ipt_add_format(b, " -A redirects -i ! %s -d %s",
-                               n->ifname, inet_ntoa(r->dest_ip->addr));
-                       fwd_ipt_add_proto(b, r->proto);
-                       fwd_ipt_add_srcport(b, r->src_port);
-                       fwd_ipt_add_destport(b, r->src_dport);
-                       fwd_ipt_add_format(b, " -j MASQUERADE");
-                       fwd_ipt_add_comment(b, "redir", z, n, NULL);
-                       fwd_ipt_exec(b);
+                       if( (x = fwd_xt_init_rule(h_nat)) != NULL )
+                       {
+                               fwd_xt_parse_in(x, n, 1);                                       /* -i ! ... */
+                               fwd_xt_parse_dest(x, r->dest_ip, 0);            /* -d ... */
+                               fwd_xt_parse_proto(x, r->proto, 0);                     /* -p ... */
+                               fwd_r_add_sport(x, r->src_port);                        /* --sport ... */
+                               fwd_r_add_dport(x, r->src_dport);                       /* --dport ... */
+                               fwd_xt_get_target(x, "MASQUERADE");                     /* -j MASQUERADE */
+                               fwd_r_add_comment(x, "redir", z, n, NULL);      /* -m comment ... */
+                               fwd_xt_exec_rule(x, "loopback");                        /* -A loopback */
+                       }
                }
        }
 
@@ -730,19 +724,21 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
                                        n->name, n->ifname, z->name, n->name, n->ifname,
                                        f->dest->name, n2->name, n2->ifname);
 
-                               b = fwd_ipt_init("filter");
-                               fwd_ipt_add_format(b, " -A rules -i %s -o %s",
-                                       n->ifname, n2->ifname);
-                               fwd_ipt_add_proto(b, c->proto);
-                               fwd_ipt_add_icmptype(b, c->icmp_type);
-                               fwd_ipt_add_srcmac(b, c->src_mac);
-                               fwd_ipt_add_srcaddr(b, c->src_ip);
-                               fwd_ipt_add_srcport(b, c->src_port);
-                               fwd_ipt_add_destaddr(b, c->dest_ip);
-                               fwd_ipt_add_destport(b, c->dest_port);
-                               fwd_ipt_add_policy_target(b, c->target);
-                               fwd_ipt_add_comment(b, "rule", z, n, n2);
-                               fwd_ipt_exec(b);
+                               if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+                               {
+                                       fwd_xt_parse_in(x, n, 0);                               /* -i ... */
+                                       fwd_xt_parse_out(x, n2, 0);                             /* -o ... */
+                                       fwd_xt_parse_src(x, c->src_ip, 0);              /* -s ... */
+                                       fwd_xt_parse_dest(x, c->dest_ip, 0);    /* -d ... */
+                                       fwd_xt_parse_proto(x, c->proto, 0);             /* -p ... */
+                                       fwd_r_add_icmptype(x, c->icmp_type);    /* --icmp-type ... */
+                                       fwd_r_add_srcmac(x, c->src_mac);                /* --mac-source ... */
+                                       fwd_r_add_sport(x, c->src_port);                /* --sport ... */
+                                       fwd_r_add_dport(x, c->dest_port);               /* --dport ... */
+                                       fwd_r_add_policytarget(x, c->target);   /* -j handle_... */
+                                       fwd_r_add_comment(x, "rule", z, n, n2); /* -m comment ... */
+                                       fwd_xt_exec_rule(x, "rules");                   /* -A rules */
+                               }
                        }
                }
 
@@ -752,19 +748,30 @@ void fwd_ipt_addif(struct fwd_handle *h, const char *net)
                        printf("\n# Net %s (%s) - rule Z:%s N:%s I:%s\n",
                                n->name, n->ifname, z->name, n->name, n->ifname);
 
-                       b = fwd_ipt_init("filter");
-                       fwd_ipt_add_format(b, " -A rules -i %s", n->ifname);
-                       fwd_ipt_add_proto(b, c->proto);
-                       fwd_ipt_add_icmptype(b, c->icmp_type);
-                       fwd_ipt_add_srcmac(b, c->src_mac);
-                       fwd_ipt_add_srcaddr(b, c->src_ip);
-                       fwd_ipt_add_srcport(b, c->src_port);
-                       fwd_ipt_add_destaddr(b, c->dest_ip);
-                       fwd_ipt_add_destport(b, c->dest_port);
-                       fwd_ipt_add_policy_target(b, c->target);
-                       fwd_ipt_add_comment(b, "rule", z, n, n2);
-                       fwd_ipt_exec(b);
+                       if( (x = fwd_xt_init_rule(h_filter)) != NULL )
+                       {
+                               fwd_xt_parse_in(x, n, 0);                                       /* -i ... */
+                               fwd_xt_parse_src(x, c->src_ip, 0);                      /* -s ... */
+                               fwd_xt_parse_dest(x, c->dest_ip, 0);            /* -d ... */
+                               fwd_xt_parse_proto(x, c->proto, 0);                     /* -p ... */
+                               fwd_r_add_icmptype(x, c->icmp_type);            /* --icmp-type ... */
+                               fwd_r_add_srcmac(x, c->src_mac);                        /* --mac-source ... */
+                               fwd_r_add_sport(x, c->src_port);                        /* --sport ... */
+                               fwd_r_add_dport(x, c->dest_port);                       /* --dport ... */
+                               fwd_r_add_policytarget(x, c->target);           /* -j handle_... */
+                               fwd_r_add_comment(x, "rule", z, n, NULL);       /* -m comment ... */
+                               fwd_xt_exec_rule(x, "rules");                           /* -A rules */
+                       }
                }
        }
+
+       if( !iptc_commit(h_nat) )
+               fwd_fatal("Cannot commit nat table: %s", iptc_strerror(errno));
+
+       if( !iptc_commit(h_filter) )
+               fwd_fatal("Cannot commit filter table: %s", iptc_strerror(errno));
+
+       iptc_free(h_nat);
+       iptc_free(h_filter);
 }